4 HI + PbO2 → I2 + PbI2 + 2 H2O

This is an oxidation-reduction (redox) reaction:

PbIV + 2 e- → PbII (reduction)

2 I-I - 2 e- → 2 I0 (oxidation)

PbO2 is an oxidizing agent, HI is a reducing agent.

Reactants:

  • HI – Iodane source: wikipedia, accessed: 2019-09-27
    • Other names: Hydroiodic acid source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Hydrogen iodide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Hydronium iodide source: wikipedia, accessed: 2019-09-27
    • Appearance: Colorless liquid source: wikipedia, accessed: 2019-09-27; Colorless gas source: wikipedia, accessed: 2019-09-27; Colourless compressed liquefied gas with pungent odour source: ICSC, accessed: 2019-09-04
  • PbO2 – Lead(IV) oxide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04
    • Other names: Lead dioxide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Plumbic oxide source: wikipedia, accessed: 2019-09-27, Plattnerite source: wikipedia, accessed: 2019-09-27, Lead peroxide source: ICSC, accessed: 2019-09-04
    • Appearance: Dark-brown, black powder source: wikipedia, accessed: 2019-09-27; Brown crystals or powder source: ICSC, accessed: 2019-09-04

Products:

  • I2
    • Names: Iodine source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Jod source: ICSC, accessed: 2019-09-04, Iode source: ICSC, accessed: 2019-09-04
    • Appearance: Bluish black or dark purple crystals with pungent odour source: ICSC, accessed: 2019-09-04; Violet solid with a sharp, characteristic odor. source: NIOSH NPG, accessed: 2019-09-02
  • PbI2
    • Names: Lead(II) iodide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Plumbous iodide source: wikipedia, accessed: 2019-09-27
    • Appearance: Bright yellow powder source: wikipedia, accessed: 2019-09-27
  • H2O – Water, oxidane source: wikipedia, accessed: 2019-09-27
    • Other names: Water (H2O) source: wikipedia, accessed: 2019-09-27, Hydrogen hydroxide (HH or HOH) source: wikipedia, accessed: 2019-09-27, Hydrogen oxide source: wikipedia, accessed: 2019-09-27
    • Appearance: White crystalline solid, almost colorless liquid with a hint of blue, colorless gas source: wikipedia, accessed: 2019-09-27